59 lines
1.7 KiB
C
59 lines
1.7 KiB
C
|
/*
|
||
|
|
* Copyright 2013 Google Inc.
|
||
|
|
*
|
||
|
|
* Use of this source code is governed by a BSD-style license that can be
|
||
|
|
* found in the LICENSE file.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef SkAtomics_win_DEFINED
|
||
|
|
#define SkAtomics_win_DEFINED
|
||
|
|
|
||
|
|
/** Windows Interlocked atomics. */
|
||
|
|
|
||
|
|
#include <intrin.h>
|
||
|
|
#include <stdint.h>
|
||
|
|
|
||
|
|
//MSDN says in order to declare an interlocked function for use as an
|
||
|
|
//intrinsic, include intrin.h and put the function in a #pragma intrinsic
|
||
|
|
//directive.
|
||
|
|
//The pragma appears to be unnecessary, but doesn't hurt.
|
||
|
|
#pragma intrinsic(_InterlockedIncrement, _InterlockedExchangeAdd, _InterlockedDecrement)
|
||
|
|
#pragma intrinsic(_InterlockedCompareExchange)
|
||
|
|
|
||
|
|
static inline int32_t sk_atomic_inc(int32_t* addr) {
|
||
|
|
// InterlockedIncrement returns the new value, we want to return the old.
|
||
|
|
return _InterlockedIncrement(reinterpret_cast<long*>(addr)) - 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline int32_t sk_atomic_add(int32_t* addr, int32_t inc) {
|
||
|
|
return _InterlockedExchangeAdd(reinterpret_cast<long*>(addr), static_cast<long>(inc));
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline int32_t sk_atomic_dec(int32_t* addr) {
|
||
|
|
// InterlockedDecrement returns the new value, we want to return the old.
|
||
|
|
return _InterlockedDecrement(reinterpret_cast<long*>(addr)) + 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void sk_membar_acquire__after_atomic_dec() { }
|
||
|
|
|
||
|
|
static inline int32_t sk_atomic_conditional_inc(int32_t* addr) {
|
||
|
|
long value = *addr;
|
||
|
|
while (true) {
|
||
|
|
if (value == 0) {
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
long before = _InterlockedCompareExchange(reinterpret_cast<long*>(addr), value + 1, value);
|
||
|
|
|
||
|
|
if (before == value) {
|
||
|
|
return value;
|
||
|
|
} else {
|
||
|
|
value = before;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void sk_membar_acquire__after_atomic_conditional_inc() { }
|
||
|
|
|
||
|
|
#endif
|